BEIJING (AP) — A look at recent developments in the South China Sea, where China is pitted against smaller neighbors in multiple disputes over islands, coral reefs and lagoons in waters crucial for global commerce and rich in fish and potential oil and gas reserves:

___

EDITOR'S NOTE: This is a weekly look at the latest developments in the South China Sea, the location of several territorial conflicts that have raised tensions in the region.

___

CHINA AIRCRAFT CARRIER

China's first entirely home-built aircraft carrier has begun sea trials, underscoring how the country is building naval assets to assert its maritime claims in the South China Sea.

The still-unnamed ship left dock in the northern port of Dalian on Sunday morning to "test the reliability and stability of its propulsion and other system," the Defense Ministry said in a statement.

The Liaoning provincial maritime safety bureau issued an order for shipping to avoid a section of ocean southeast of the city between Sunday and Friday.

China has the world's largest navy in terms of numbers of vessels, although it lags behind the U.S. in technology and combat capabilities.

China's navy is largely deployed to enforce Beijing's claim to virtually the entire South China Sea and is increasingly ranging farther into the Pacific and Indian oceans. China last year established its first overseas military base in the Horn of Africa nation of Djibouti, where rivals such as the U.S., Japan and several European nations also have a permanent presence.

___

PHILIPPINES DEPLOYMENT

The Philippine navy says it will deploy its first-ever missile-firing assault vessels in about three months.

Navy chief Vice Admiral Robert Empedrad told a news conference Thursday that the navy also plans to acquire torpedoes, submarines and other major defense equipment under a modernization program.

The Philippines is a vast collection of islands with one of the world's longest coastlines. It faces threats from Islamic and communist insurgencies, piracy and other cross-border crimes, as well as encroachment from China on its island claims in the South China Sea.

Israeli-made missiles, which have a range of 8 kilometers (5 miles), are being installed in three multipurpose attack vessels that were acquired earlier and will be ready for deployment in two to three months, Empedrad said.

The Philippine military, among the most ill-equipped in Asia, has struggled in recent years to modernize its navy, air force and army.

___

VIETNAM REQUEST

Vietnam has called on China to withdraw military equipment from its South China Sea island outposts, saying they violate Hanoi's sovereignty, increase tensions and destabilize the region.

Foreign Ministry spokeswoman Le Thi Thu Hang said in a statement Wednesday that Vietnam has sufficient legal basis and historical evidence to affirm its sovereignty over the Spratly and the Paracel island groups in the South China Sea. The islands are largely occupied by China.

China has constructed seven man-made islands and equipped them with runways, hangers, radar and missile stations, further cementing its vast territorial claims in the busy waterway.

___

US-PHILIPPINES EXERCISES

U.S. and Philippine forces began their largest annual military exercises since President Rodrigo Duterte came to power with a vow to scale back America's military presence in the country.

The Balikatan exercises opened last Monday with a ceremony at the main Philippine military camp in Manila. They feature about 8,000 American and Filipino personnel along with small contingents from Japan and Australia.

The exercises are "just one of many embodiments of our robust relationship," U.S. Ambassador Sung Kim said, referring to the long-standing security alliance between the two countries.

After taking power in 2016, Duterte vowed to scale back the presence of U.S. troops involved in counterterrorism training in the country's south. He also once threatened to end the annual drills with American forces.

The volatile leader has long criticized U.S. security policies and has taken steps to revive ties with China that had been strained under his predecessor over longstanding territorial conflicts in the South China Sea.